The present invention relates to the general field of aviation turbine engines, and in particular turbojets. More particularly, it relates to a device for protecting the full authority digital engine control (FADEC) and that is capable under all circumstances of ensuring that the FADEC is maintained on a portion of the casing of the engine.
In most aeroengines presently in service, the FADEC is fastened to the fan casing, and thus in a zone that is particularly sensitive to fire. Specifically, installing the FADEC in a non-fire zone (i.e. a zone in which it is not possible for flammable liquids to meet a source of ignition) that is spaced apart from the engine compartment by firewalls, or indeed installing the FADEC in the fuselage of the airplane, would lead to severe constraints in terms of installation, and to impacts on weight and to extra cost as a result of the additional connections and difficulties of maintenance.
The FADEC is conventionally fastened by supports/fittings made of mechanically welded stainless steel sheets that must therefore withstand fire while also protecting the electronic components of the computer from the vibration that might be generated by a potential unbalance on the rotors of the engine and that must be capable of withstanding accelerations up to 150 g. Another object of such supports is to preserve minimum spacing between the casing and the bottom of the FADEC housing, said spacing being of the order of a few tens of millimeters (typically 40 mm), firstly so as to ensure that air can flow between the casing and the FADEC, since the electronic components of a computer generate heat that needs to be removed by convection and radiation, and secondly to avoid physical contact between the casing and the FADEC in the event of a blade being lost. If there is an impact of a blade against the casing, the casing may be subjected to a large amount of deformation.
Those constraints that bear on the connection via supports are therefore not without drawbacks. Firstly the resulting structure is particularly heavy, which is most unwelcome in the field of aviation in which any reduction in on-board weight is welcome, and secondly that structure requires a large number of distinct components in order to be implemented, thereby involving industrial management that is burdensome and expensive.